^ AaRICULTURAL BOTANY. 627 



claims that catalase is the primary factor in alcoholic fermentatiou, and there- 

 fore probably in I'espiration. 



Id conclusion the author states that the changes peculiar to the after-ripening 

 of the potato tuber may be brought about by changes in the bud and not In 

 the tuber as a whole. 



On the influence of fermentation products and phosphates upon respiration 

 in plants, S. Kostytschew and A. Scheloumow {Jahrh. Wiss. Bot. [Prings- 

 heim], 50 {1911), No. 2, pp. 157-109).— The autliors state that they expect to 

 throw light upon the relations between the carbon dioxid exhalation of plants 

 and alcoholic fermentation, and thereby upon the mechanism of respiration in 

 general, studying the problem in the light of the discovery (according to recent 

 conclusions) that not acid exhalation alone but alcoholic fermentation as well 

 depends upon the influence of the phosphates. The article, besides giving de- 

 tails of the authors' researches, attempts (1) to state briefly the known perti- 

 nent facts, (2) to separate the experimentally based from the hyiwthetical 

 views, and (3) to render judgment as to the plausibility of the latter. 



Experiments were carried out in the evolution of carbon dioxid by wheat 

 embryos in solutions of phosphates, hydrates, grape sugar, and fermentation 

 products. The principal conclusions arrived at may be summarized as follows : 



(1) The operation of the phosphates upon carbon dioxid production is essen- 

 tially the acceleration of carbon dioxid formation through an alkaline reaction. 



(2) In neutral solutions phosphate ions have only a very small stimulating 

 effect which expresses itself only in dilute solutions ; even 3 per cent solutions 

 have very slight influence. (3) The stimulating influence of alkaline reactions 

 on carbon dioxid production occurs without an addition of phosphate, but 

 that of the phosphate is greater. (4) Fermentation products give a surprising 

 increase of carbon dioxid production when added to phosphate solutions. (5) 

 Sugar solutions treated for 5 hours with ferments show a greater influence 

 on carbon dioxid production than fermentation extracts alone. 



The relation of transpiration and stomatal movements to the water con- 

 tent of the leaves of Fouquieria splendens, F. E. Lloyd {Plant World, 15 

 {1912), A'o. 1, pp. 1-14, dgm. 1). — In continuation of a previous report (E. S. R., 

 25, p. 124), an account is given of comparative volumetric and gravimetric 

 observations which show that in Fouquieria the ratio between intake and outgo 

 of water is not constant, but that the outgo during the day is greater than the 

 intake. The reverse condition obtains during the night. The decrease of water 

 in the leaf occurs during the opening of the stomata. These organs are not 

 closely regulatory of the water loss from the leaf and are ineffectual in main- 

 taining a constant water content. It appears that transpiration, therefore, 

 at times may be too great, and that stomata do not serve to reduce it by closing 

 movements; they may, however, limit it in a passive manner. 



Observations on the degree of stomatal movement in certain plants, B. E. 

 Livingston and A. H. Estaerook {Bui. Torrey Bot. Cluh, 39 {1912), No. 1. 

 pp. 15-22). — A study was made to determine the opening and closing of stomata 

 in a large number of plants at various periods of the day. The plants used 

 were Funkia ovata, Isatis tinctoria, Allimn cepa, Eichhornm speciosa, and 

 CEnothera biennis. 



It was found that all the stomata were open at the daylight hour of observa- 

 tion while the majority were closed at night. The diffusive capacity of the 

 stomata appears to be approximately 8.2 per cent as great at about midnight 

 as at 3 o'clock in the afternoon. 



Experipients were conducted to determine the diffusive capacities of the 

 stomata of the different leaves. This capacity reached the zero point at night 

 in all cases excepting with Allium, Eichhornia, and the lower leaf surface of 



